Hinge assembly for furnace doors



Feb. 23, 1954 B, MQRSE 2,670,197

HINGE ASSEMBLY FOR FURNACE DOORS Filed Oct. 19, 1949 Yaanl.

Patented Feb. 23, 1954 UNITED STATES PATENT OFFICE 7 3,670,113.! uGe-AssEMeLY FO U r s Gl nn B. Morse, Grand Rapids; Mich... Applica ionOct ber 19, 4 Se a No, 12 ,300

' 2 Claims.

The present invention prov-ides a door-closing mechanism primarily forthe doors of furnaces. When the usual coal furnace is converted for theuse of gas, it is preferable to provide the door with some sort of abiasing device in order to assure that the door is not inadvertentlyleft open so that the flow of air in the combustion chamber is altered,and also to assure that the door does not remain open after an explosionwithin the furnace. It is the general practice to meet theserequirements by replacing the conventional hinge pins with a continuouspin spanning both upper and lower hinges, and to mount upon thiscontinuous hinge pin a helical spring having extended ends. One of theseends is disposed to bear upon the furnace door, and the other to bearagainst the front of the furnace. When the spring is assembled in thisposition, a twist is applied to assure that enough initial torsion isgenerated to assure the proper function of the assembly. When theassembly discussed above (which is well known) is incorporated in afurnace, situations will inevitably arise when it is desired to l avethe door in an pen, position temporar r he s rvice or nspection oi thinterior of the. furnace. It is decid dly inconvenient for a servicemento be forced to carry with him a series of locks or other steps t be plaed be: tween he door and th fu na e in, order to hold the door open. orbe required to, resort to. the attachment of a wire or rope to someconvenient post tor this purpose.

It may be noted that an undesirable characteristic of the elementaryhinge assembly previously discussed is the extreme diflicultyof applyingthe required initial twist to the spring asthe Spring and hinge rod areassembled in position. It is necessary to properly support the door inposition for the hinge pin to cooperate with the hinge fittings, and atthe same time to Place the spring in position on the rod and apply therequired torque. While holding the the. ends of the spring withoutinjury to the finsets. ob iously. th s r u e requires either a highdegree a: dexterity and consummate skill, or the service o at ea t o Ths ac lu the act tha the opera ion. c nnot b reduced to routin due odiiicrences in ontour or various iumasss results a rather high an diation cost for this type of equipment.

The present invention provides an added component to the hinge assembleddiscussed above having a double purpose. The principal purpose of thiscomponent is to provide a locking action securing the ends of the springin a predeter mined relationship comparable to the position these endswould assume when the door is in the extreme open position. Locked inthis angular relationship, it follows that the biasingaction normallypresent against the furnace door is completely removed. The door canthen be left in whatever position desired for service or inspection ofthe interior of the furnace, When such work has been completed, therestraining action of this added component is removed from the springand the biasing action restored to the door. Since thistype ofcomponent'makes it possible to secure the spring in the open position itfollows that the component may be assembled to the spring at the factoryso that the mechanic may assemble the components oi; the hinge withoutthe necessity of applying a torque to the spring. It is merely necessaryto slip. the spring onto the hinge rod, and then bring the r d, n i s naly ssembled positi n. Wh this operation has been performed, the door canbe s ng o a position s i htly b yond the ino mally open. thus applying atorque, to the prin nd permitt ng th release of the restrainingcomponent. The fu biasin action of he pring is then applied directly tothe door, and the inter: totin co pon nt o stop s l ft n a inactiveposition until it is again desired to leave th door open 501 an extendedperiod.

Essentially, the structure of the stop includes an engaging sectiondisposed to cooperate with each of the ends of the helical spring, and atorque=transfer section connecting these en-' gaging points. Since thetwist at one end will of course exactly balance the twist at the other,the ends of the spring will be securely locked in a. predeterminedangular relationship as soon as the engaging means are brought to bearupon their respective ends of the spring. To facilitate the attachmentof this component to the assemb y, it is re a le :for e end of t e s rinto be engageable with the step through a slot arranged generallyparallel to the axis of the hin b y. A th opp site p ie abl the w r enor thi component a n tch s provided h h is ssessable ith the relate oneat he ica sl des The stop member he slid in a. vertical direction enoughto permit the en-' gagement of the notch at the lower end with thespring, and it will be seen that the dimensions of the stop memberitself will be determined entirely by the axial length of the helicalspring.

Since the reaction at the notch and also at the elongated slot are in agenerally tangential direction, it follows that means must be providedon the stop member for converting these forces into torque which can betransferred to the opposite end of the stop member. For this purpose, aformed section is preferably provided partially surrounding the outerdiameter of the helical spring and arranged to oppose the linear forcesgenerated at the point of engagement of the spring ends with theengaging means. A variety of e uivalent arrangements can be used toperform this function, such as the provision of suitable apertured bentears at opposite ends of the stop device disposed to cooperate with thehinge shaft. Any such arrangement having the general function ofmaintaining the axial alignment of the stop member with respect to thespring will be adeouate, but the svstem described above and illustratedin the drawings is preferable due to the simplicity of manufacture andassembly associated therewith.

The particular features of the present invention will be discussed indetail by analysis of the embodiments illustrated in the accompanyingdrawings. In these drawings,

Figure 1 is a view'in elevation of a conventional furnace door providedwith a hinge assembly embodyin the present invention.

Figure 2 is a view taken in elevation of the mechanism sho n in Figurel. with the stop com onent in the locked position and showing thefurnace door free from the biasing action of the spring. With thecomponents in the position shown in Figure 2. the as emblv including thehelical spring and the stop is free to slide axially along the rod, butis shown in the position indicated for clarity. 1

Fi ure 3 is a section taken on the plane 3-3 of Figure 2.

Figure 4 is a section taken on the plane 4-4 of Figure 1.

Referring to Figure 1, the furnace door generally designated as H) ishinged upon the axis H by the cooperatin action of the hinge members,i2. i3, i4, and i5, and also the hinge rod IS. The helical spring I! isprovided with the tangentially extending arms i8 and IS. The arm [8bears against the edge of the furnace door It, and the arm l9 bearsagainst the front of the furnace 20.

The stop member 2! is provided with an elongated slot 22 adapted tocooperate with the end 18 of the spring. As will be noted in Figures 3and 4, the slot 22 is disposed in a tangential portion 23 of the stopmember, and the notch 24 at the opposite end of the stop member 2| isdisposed in a tangential portion 25. To obtain the desired angularrelationship, it will be noted that (in the device illustrated in thesedrawings) an approximately 30 degree angle exists between the planes ofthese two portions of metal.

To oppose the tangential forces generated at the slot 22 and at the hook24, formed sections 26 and 21 are provided. It will be noted that theformed section 26 reaches around approximately 90 degrees of the outerperiphery of the helical spring with respect to the tangential portion23, and that the formed ssqiiop. 21 has a similar relationship with thetangential portion 25. The interaction of the engaging points and theformed portions result in a generation of torque at each end of thespring which is in direct opposition to the torque generated at theopposite end. If it were not for the formed sections 25 and 21, or theirequivalent, the stop member would simply tend to rotate in acounterclockwise direction as shown in Figure l as soon as the engagingends are brought to bear upon the spring. As noted above, a greatvariety of equivalent means are readily available for the prevention ofsuch displacement of the stop member with respect to the axis of thespring.

With the illustrated device, the spring and the stop member can beplaced in a position shown in Figure 2 and the article supplied forinstallation in that condition. With the angular relationship of thespring ends it and I9 thus determined, it is obvious that thesecomponents can be simply slipped onto the hinge rod 16 after passing therod through either the upper or lower hinge members, since the assemblyof the spring and the stop permit easy axial movement along the rod. Thebiasing action can be applied to the door by simply urging the door inthe open direction far enough to permit the notch 24 to pass over anddisengage the end of the spring l9. This movement will of course involvesome axial displacement ofthe stop member, and this is accommodated bythe slot 22 while still maintaining the stop member in assembledrelationship with the other components. Such a stop member may beaddedto an already existing assembly involving a helical spring by therotating of the spring end l8 far enough to permit the engagement of thestop member at the elongated slot. After the stop member has been shovedinto the position shown in Figure l, the spring end can be released toagain bear upon the furnace door.

The appended claims are intended to be comprehensive of allmodifications of the invention coming within their scope.

I claim: I

1. In combination with a helical spring having tangentially projectingends, a lock for establishing relatively angular relationship of theends of said spring comprising: first and second engaging means adaptedto cooperate respectively with the ends of said spring, said engagingmeans each including a stop disposed to bear against the'respeotive endof said spring, and also including an opposite aligning member, saidaligning member being disposed to cooperate with the side of said springin abutting relationship at points thereon where a radius to the axis ofsaid spring is substantially parallel to the direction of the forceapplied to said stop by the end of said spring, and torque-transfermeans fixing the relative position of said first and second engagingmeans so as to maintain an angular relationship of the ends of the saidsprings substantially less than degrees against a biasing action of saidspring tending to increase said angular relationship.

2. In combination with a helical spring having tangentially projectingends, a lock for establishing relatively angular relationshipbetween'the ends of said spring, comprising: a plate having slots onopposite sides separating each of said sides into at least two portions,one of said p01 tions on each side having a stop disposed to bearagainst the respective end of said spring-{the opposite portiontherefrom on the other side of said plate being disposed to cooperatewith the side of said spring in abutting relationship at points thereonwhere a radius to the axis of said spring is substantially parallel tothe direction 5 of force applied to said stop by the end of said spring.

GLENN B. MORSE.

me Date Number Na olvis Jan. 3, 1950 Number FOREIGN PATENTS Country DateDenmark Oct. 23, 1913 Great Britain Feb. 5, 1914 Great Britain Feb. 20,1935

